Targeted Therapy

Targeted therapies are cancer treatments that stop or slow the spread of cancer by interfering with specific areas of cancer cells that are involved in the cancer cell’s growth processes. Targeted therapy is different than chemotherapy, which focuses on cells that divide and grow quickly. Chemotherapy cannot distinguish between fast-growing cancer cells and fast-growing healthy cells in the body, like cells in the digestive tract, hair, bone marrow, and blood, and can cause multiple side effects. Targeted therapy focuses on other specific features of cancer cells, in an effort to provide treatment for cancer that does less damage to normal cells and tends to cause fewer side effects.1,2

Targeted therapy is also different from chemotherapy in the way it affects cancer cells. Targeted therapies are generally cytostatic, meaning they block the growth or spread of cancer cells. Chemotherapy drugs are typically cytotoxic, meaning they kill cancer cells.2

Types of targeted therapy

There are different types of targeted therapy that are used to treat certain blood cancers, including monoclonal antibodies, tyrosine kinase inhibitors (TKIs), proteasome inhibitors, and histone deacetylase (HDAC) inhibitors.

Monoclonal antibodies are created in the laboratory to identify and block cancer growth or kill cancer cells. Examples of monoclonal antibodies used to treat certain blood cancers include:

Daratumumab (brand name: Darzalex®)3

Elotuzumab (brand name: Empliciti™)3

Rituximab (brand name: Rituxan®)4

Ibritumomab tiuxetan (brand name: Zevalin®)4

TKIs target a specific protein that is found on certain cancer cells. Examples of TKIs used to treat certain blood cancers include:

Imatinib mesylate (brand name: Gleevec®)

Nilotinib (brand name: Tasigna®)

Dasatinib (brand name: Sprycel®)

Ibrutinib (brand name: Imbruvica®)

Acalabrutinib (brand name: Calquence®)

Ponatinib (brand name: Iclusig®)5

Proteasome inhibitors block the action of proteasomes (substances which remove proteins inside cancer cells), which can help cause the proteins to increase in the cancer cell and can lead to the cancer cell’s death. Examples of proteasome inhibitors used to treat certain blood cancers include:

Bortezomib (brand name: Velcade®)

Carfilzomib (brand name: Kyprolis®)

Ixazomib (brand name: Ninlaro®)3

Histone deacetylase (HDAC) inhibitors block enzymes that are important for cell division and may block the growth of cancer cells. An example of an HDAC inhibitor used in certain blood cancers is panobinostat (brand name: Farydak®).3

Common side effects of targeted therapies

Targeted therapies can cause side effects. Side effects are dependent on the type, and dosage, of the drugs given. Some common side effects include:

Gastrointestinal perforation (a rare side effect that causes a hole in the intestines)2

Most side effects from targeted therapies are temporary and tend to go away after treatment is completed. Many of the side effects can be managed or prevented. Communication between patients and their health care team is critical, and any side effects experienced should be brought to the attention of a doctor or nurse.2

How targeted therapy is given

Targeted therapies may be delivered in a pill form to take by mouth, or they may be injected into a vein. The frequency and length of treatment depends on the type of blood cancer a person has, and the type of targeted therapy being used. Some targeted therapies are taken daily, while others may be administered weekly or monthly.2